Inside micrometer



June 1, 1965 w. BINDER INSIDE MICROMETER Filed Nov. 13, 1963 Ill E SE

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United States Patent 3,186,093 INSIDE MICROMETER Wolfgang Binder, Walden, N.Y., assignor of fifty percent to Gerhard Kersten, Walden, N.Y. Filed Nov. 13, 1963, Ser. No. 323,392 6 Claims. (Cl. 33-164) This invention relates to a novel and useful inside micrometer and more specifically to a micrometer constructed in a manner whereby it may be readily inserted an appreciable distance in a bore for the purpose of determing the out-of-roundness or the taper of the bore.

The inside micrometer of the instant invention comprises an elongated main body portion having an abutment on one end and an extendible end portion which is threadedly engaged with the main body portion and may be rotated relative to the latter in order to extend the over-all length of the body of the-micrometer. While this construct-ion is not unlike various forms of micrometers presently in use, the inside micrometer of the instant invention is constructed in a manner whereby it is provided with an elongated laterally directed handle with actuating means on the free end of the handle and drivingly coupled to the rotatable extendible portion of the body.

While several forms of inside micro-meters provided with laterally directed handles have been heretofore designed, these have included Vernier scale means or the like for reading the setting of the micrometer and connected between the relatively movable portions of the micrometer by means ofvarious methods which inherently provide slack between the extendible portions of the micrometer and the relatively movable portions of the Vernier scale means. With this type of construction any slack or wear present results in an inaccurate reading andtherefore previously known inside micrometers provided with laterally directed handles of the type hereinbefore described have been unable to render continuously accurate service.

It is therefore the main object of this invention to provide an inside micrometer of the type including a laterally directed handle for placing the micrometer an appreciable distance within a bore and constructed in a manner whereby a reading may be given with accuracy equal to the accuracy afforded by conventional micrometers.

Still another object of this invention is to provide an inside micrometer constructed in a manner whereby eX- tension adapters may be readily removably secured thereto.

Another object of this invention is to provide an inside micrometer in accordance with the preceding objects and including two relatively movable and threadedly engaged members including a threaded connection with each other having means for adjusting the clearance between the two threadedly connectedmembers.

A final object of this invention to be specifically enumerated herein is to provide an inside micrometer which will conform to conventional forms of manufacture, be of simple construction and easy to use so as to provide a device that will be economically feasible, long lasting and relatively trouble free in operation.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numeral-s refer to like parts throughout, and in' which:

FIGURE 1 is a perspective view of the inside micrometer of the instant invention;

FIGURE 2 is an enlarged longitudinal horizontal sectional view taken substantially upon the plane passing through the longitudinal centerline of the micrometer;

FIGURE 3 is 'a sectional view taken substantially upon the plane indicated by the section line 3- 3 of FIGURE 2;

IFIGURE 4 is a fragmentary sectional view taken substantially upon the plane indicated by the section line 4-4 of FIGURE 2;

FIGURE 5 is a fragmentary sectional view similar to the lower left hand portion of FIGURE 2 but showing an extension attachment secured to the body of the micrometer; FIGURE 6 is a side elevational view of the upper left hand portion of the embodiment illustrated in FIGURE 2 and with the cap shown in longitudinal section; and

FIGURE 7 is a fragmentary top plan view of the right hand side of the embodiment illustrated in FIGURE 2.

Referring now more specifically to the drawings, the numeral 10 generally designates the inside micrometer of the instant invention which includes a body or head generally referred to by the reference numeral 12, a cap generally referred to by the reference numeral 14 and a handle generally referred to by the reference numeral 16.

The central portion of the body or head 12 is generally rectangular and is hollow and has one end of the handle 16 threadedly secured in a threaded aperture 18 formed in one wall thereof. The handle 16 includes a radially outwardly projecting shoulder 28 which abuts against the outer surface of the apertured wall and provides a seating surface for the handle 16.

A drive shaft 22 is journalled through the handle 16 and has a worm gear 24 formed on the end there-of disposed within the body or head 12. In addition, it may be seen from FIGURE 3 of the drawings that the drive shaft 22 also includes a radially outwardly projecting abutment flange 26 which abuts against the inner end of the handle 16 and prevents outward retraction of the drive shaft 22. A knob 28 is secured to the outer end of the drive shaft 22 by means of a setscrew 3t and the drive shaft projects through the knob 28 and has a turning knob 32 journalled thereon. The knob 28 and turning knob 32 include meshed ratchet teeth 34 and 36 respectively and the turning knob 32 is retained on the drive shaft 22 by means of a fastener 38 and is yieldingly urged into engagement with the teeth 34 by means of the compression spring 40 disposed in the recess 42 formed in the turning knob 32 and abutted against the undersurface of the head of the fastener 38.

One end of the body or head 12 defines an externally threaded shank 44 which terminates at its free end in a rounded feeler abutment 46. 'The externally threaded shank 44 is hollow and defines a bore 48 which is aligned with a bore 50 formed in the other end of the body 12. The bores 48 and 50 are axially spaced and communi cated by a central cavity 52 formed in the body 12 and into which the drive shaft 22 and worm gear 24 project.

The cap 14 is telescoped over a sleeve portion 56 remote from the shank 44. The sleeve portion 56 defines the bore 50 and the outer end of the bore 50 is internally threaded as at 58. Further, the free terminal end portion of the sleeve portion 56 is longitudinally slotted as at 68. In addition, the free terminal end portion of the sleeve portion 56 is tapered toward its free end and externally threaded as at 62. An adjusting nut 64 is threadedly engaged with the free terminal end portion of the sleeve portion 56 and the cylindrical cap 14 which includes an outer end Wall 66 is telescoped over the sleeve portion 56. The end wall 66 of the cylindrical cap 14 has an axially projecting stud 68 secured therethrough by means of a nut 70. The end wall 66 includes a centrally disposed frusto-conical bore 72 in which the stud 68 is seated. The free outer end of the stud 68 defines a feeler abutment 76 which faces in a direction away from the feeler abutment 46.

The stud 68 is threadedly engaged in the internally threaded portion 58 of the bore 50 and includes a diametrically reduced portion 78 remote from the abutment 76 which is longitudinally grooved as at 80 and has a key 82 seated in the groove 80.

A gear wheel 84 is mounted on the diametrically reduced end portion 7 8 of the stud 68 and is keyed thereto by means of the key 80. However, the opposite side Walls 86 and 88 of the body 12 comprise thrust bearing surfaces for the gear wheel 84 preventing axial shifting of the latter relative to the body 12 and the diametrically reduced portion 78 of the stud 68 may be shifted axially of the gear wheel 84.

As can best be seen from FIGURE 1 of the drawings, the sleeve portion 56 and the cap 14 include external indicia 90 and 92 of the conventional type and which may be utilized to indicate the distance between the remote surfaces of the feeler abutments 46 and '76.

The nut 64 is utilized to adjust the clearance between the threadedly engaged portions of the stud 68 and sleeve 56 and it will be apparent that upon rotation of the knob 28 and shaft 22 that the stud 68 will be rotated relative to the body 12 whereupon different ones of the indicia 90 and 92 will be brought into registry with each other as the over-all length of the body 12 is increased or decreased.

As can best be seen in FIGURE 5 of the drawings, the externally threaded shank 44 may have an extension cap assembly 94 threadedly engaged therewith including a cylindrical portion 96, a threaded end plug 98 and a lock or jamnut 109. The exposed end of the plug 98 defines a further feeler abutment 102 and it will be noted that the extension cap 94 may be utilized to extend the over-all length of the body 12 of the micrometer 1d a given distance.

In operation, the inside micrometer 10 may be grasped by the free end of the handle 16 and inserted into a bore. Thereafter, the knob 28 may be rotated in order to extend the over-all length of the body 12 by screwing the shank 68 outwardly of the threaded portion 58 of the bore 50. After the micrometer has been extended to the full diameter of the bore, it may be slightly cocked in the bore and withdrawn therefrom in order that the indicia 96 and 92 may be read. Additional measurements may of course be made to obtain an average measurement and to check various portions of the bore for out-of-roundness or taper.

If it is desired, the friction clutch defined between the knob 28 and the turning knob 32 by means of the meshed teeth 34 and 36 and the compression spring 40 may be utilized in order to maintain the same touch each time a measurement is made with the micrometer 10.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and charges will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed.

What is claimed as new is as follows:

1. An inside micrometer comprising an elongated body defining an internally threaded longitudinally extending sleeve portion at one end portion thereof, a cap telescoped over said sleeve portion and including an externally threaded stud threadedly engaged in said sleeve and rotatable with said cap, oppositely facing abutment means on said other end of said body and said cap, registering indicia formed on said body and cap, elongated handle means projecting outwardly of one side of said body having a longitudinally extending drive shaft journaled therethrough and extending into said body, a gear wheel mounted on said stud inwardly of the threaded portion of said stud and retained against axial shifting relative to said body, said stud being keyed to said gear wheel for rotation therewith and longitudinal shifting relative thereto, and a worm gear mounted on said drive shaft and meshed with said gear wheel.

2. The combination of claim 1 wherein the free end portion of said sleeve portion is longitudinally slotted, externally tapered toward its free end, and externally threaded, and an adjusting nut threaded on said tapered end portion.

3. The combination of claim 2 wherein said cap is of a length to completely enclose said externally threaded tapered end portion and said adjusting nut.

4. The combination of claim 1 wherein said abutment means on said cap includes means mounting for adjustably rotatably positioning said cap about said stud.

5. The combination of claim 1 wherein said other end of said body defines an externally threaded shank, a removable extension abutment cap threadedly engaged on said shank and enclosing the abutment on said other end of said body, said extension abutment cap including abutment means facing away from said other end of said body.

6. The combination of claim 1 wherein said drive shaft has a turning knob journalled on the free end thereof remote from said worn gear, and a friction clutch drivingly coupling said turning knob to said shaft.

References Cited by the Examiner UNITED STATES PATENTS 1,463,673 7/23 Close 33-164 2,220,378 11/40 Muller 33-164 2,466,916 4/49 Stedman 33167 2,606,370 8/52 Hicks 33-164 2,607,999 8/52 Stedman 33167 2,649,782 8/53 Smith 33-164 FOREIGN PATENTS 405,871 2/34 Great Britain.

ISAAC LISANN, Primary Examiner. 

1. AN INSIDE MICROMETER COMPRISING AN ELONGATED BODY DEFINING AN INTERNALLY THREADED LONGITUDINALLY EXTENDING SLEEVE PORTION AT ONE END PORTION THEREOF, A CAP TELESCOPED OVER SAID SLEEVE PORTION AND INCLUDING AN EXTERNALLY THREADED STUD THREADEDLY ENGAGED IN SAID SLEEVE AND ROTATABLE WITH SAID CAP, OPPOSITELY FACING ABUTMENT MEANS ON SAID OTHER END OF SAID BODY AND SAID CAP, REGISTERING INDICIA FORMED ON SAID BODY AND CAP, ELONGATED HANDLE MEANS PROJECTING OUTWARDLY OF ONE SIDE OF SAID BODY HAVING A LONGITUDINALLY EXTENDING DRIVE SHAFT JOURNALED THERETHROUGH AND EXTENDING INTO SAID BODY, A GEAR WHEEL MOUNTED ON SAID STUD INWARDLY OF THE THREADED PORTION OF SAID STUD AND RETAINED AGAINST AXIAL SHIFTING RELATIVE TO SAID BODY, SAID STUD BEING KEYED TO SAID GEAR WHEEL FOR ROTATION THEREWITH AND LONGITUDINAL SHIFTING RELATIVE THERETO, AND A WORM GEAR MOUNTED ON SAID DRIVE SHAFT AND MESHED WITH SAID GEAR WHEEL. 